Systems and methods for targeting directed energy devices

ABSTRACT

Systems and methods for targeting a directed energy system are provided. A particular system includes a first laser and a second laser. The system also includes a scanning system coupled to the first laser and the second laser. The scanning system is adapted to movably direct the second laser in a pattern around a pointing location of the first laser.

FIELD OF THE DISCLOSURE

The present disclosure is generally related to targeting directed energydevices.

BACKGROUND

Advances in technology have led to the development of directed energydevices that may be used to attack targets. Directed energy devices maybe useful for airborne targets that move relatively quickly. Targetingsystems for directed energy devices may include imaging systems that aimthe directed energy devices at the target based on optical images of thetarget. Gathering and analyzing imaging data may be time consuming andcomputationally challenging and may be subject to atmosphericinterferences. Other directed energy devices may be targeted bydiverting a portion of a primary energy beam for sampling to determine apointing direction of the primary energy beam relative to the target orby sensing the pointing direction of the primary energy beam based onreflected energy of the primary energy beam. Using reflected energy ofthe primary beam for targeting typically means that some portion of theenergy of the primary energy beam is not focused on the targeted and istherefore wasted. Hence, improved systems and methods of targetingdirected energy devices are needed.

SUMMARY

Systems and methods for targeting a directed energy system are provided.A particular system includes a first laser and a second laser. Thesystem also includes a scanning system coupled to the first laser andthe second laser. The scanning system is adapted to movably direct thesecond laser in a pattern around a pointing location of the first laser.

In another particular embodiment, a method includes shining a firstlaser onto a target and moving the first laser in a curvilinear patternover the target. The method also includes detecting reflections of thefirst laser from the target. The method further includes pointing asecond laser at the target based on the detected reflections.

In another particular embodiment, a control system includes a detectorinterface to receive a detection signal including information regardingdetected reflections of a targeting laser. The control system alsoincludes a scanning module to determine a curvilinear scanning patternin which to move the targeting laser based on target information relatedto a target. The control system further includes a targeting module todetermine when a center of the curvilinear scanning pattern coincideswith a targeting location on the target based on the detectedreflections.

In another particular embodiment, a computer-readable medium includesinstructions that, when executed by a processor, cause the processor todetermine a curvilinear scanning pattern based on information related toa target. The computer-readable medium also includes instructions that,when executed by the processor, cause the processor to determine when acenter of the curvilinear pattern substantially coincides with atargeting location on the target based on detected reflections from thetarget.

The features, functions, and advantages that have been discussed can beachieved independently in various embodiments or may be combined in yetother embodiments further details of which can be seen with reference tothe following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a first embodiment of a directed energy system;

FIG. 2 is a block diagram of a second embodiment of a directed energysystem;

FIG. 3 is a diagram of a third embodiment of a directed energy system;

FIG. 4 is a diagram illustrating a first embodiment of a method oftargeting a directed energy device;

FIG. 5 is a diagram illustrating a second embodiment of a method oftargeting a directed energy device;

FIG. 6 is a diagram illustrating a third embodiment of a method oftargeting a directed energy device;

FIG. 7 is a diagram illustrating a fourth embodiment of a method oftargeting a directed energy device;

FIG. 8 is a diagram illustrating a fifth embodiment of a method oftargeting a directed energy device;

FIG. 9 is a diagram illustrating a sixth embodiment of a method oftargeting a directed energy device;

FIG. 10 is a flow chart of a particular embodiment of a method oftargeting a directed energy device; and

FIG. 11 is a diagram illustrating reflection signals from a targetingsystem.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a first particular embodiment of a directed energysystem, designated generally 100. The directed energy system 100includes two or more directed energy devices, such as a first laser 102and a second laser 120. In another particular embodiment, the directedenergy system 100 includes one or more other types of directed energydevices, such as, but not limited to a maser device, a particle beamdevice, or another device adapted to emit light, electromagneticradiation or energetic particles in a directional manner.

The directed energy system 100 provides a mechanism for targeting thefirst laser 102 such that a primary beam 122 projected from the firstlaser 102 strikes a target 108 at a targeting location 110. The target108 may include a missile, a rocket propelled grenade, a mortar round,an artillery round, an aircraft, or another airborne, land-based,water-based, or space-based target. The directed energy system 100 maybe stationary or mobile. Additionally, the directed energy system 100may be land-based, ship-based, airborne (e.g., onboard an airplane orother aircraft) or space-based (e.g., onboard an orbiting satellite). Ina particular illustrative embodiment, the first laser 102 is a highenergy laser capable of damaging or destroying the target 108 from arelatively large distance and the second laser 120 is a lower energypower capable of generating a scanning beam 104 with enough energy forreflections 112 of the beam 104 to be detected by a detector 114 of thedirected energy system 100.

In a particular embodiment, the directed energy system 100 includes acontroller 124 adapted to control the first laser 102 and the secondlaser 120. For example, the first laser 102 may emit the primary beam122 via the optics 118 in response to a fire signal received from thecontroller 124. The second laser 120 may be adapted to emit the scanningbeam 104 via the optics 118 in response to a scan signal from thecontroller 124. Thus, at least a portion of the optics 118 may be sharedby the first laser 102 and the second laser 120.

The scanning beam 104 may be moved in a curvilinear pattern 106 via thescanning system 116. The scanning system 116 may be coupled to the firstlaser 102 and the second laser 120 and may be adapted to moveably directthe scanning beam 104 in the curvilinear pattern 106 around a pointinglocation of the first laser 102. For example, the scanning system 116may include a mirror adapted to rotate or otherwise move the scanningbeam 104 from the second laser 120 to scan the target 108. Thecurvilinear pattern 106 may include a circle, an ellipse, anothercurvilinear pattern (such as a Lissajous loop), or any combinationthereof.

In a particular embodiment, the controller 124 is adapted to determinewhen the first laser 102 is pointed at the targeting location 110 on thetarget 108 based on the detected reflections 112 of the scanning beam104. For example, the reflections 112 from the scanning beam 104 may bereceived by the detector 114. The detector 114 is adapted to detectreflected energy of the scanning beam 104 from the target 108 and toprovide a detection signal related to the reflected energy to thecontroller 124. The controller 124 may receive the detection signal andmay determine, based on the detection signal, when a center of thecurvilinear pattern 106 substantially coincides with a targetinglocation 110 on the target 108. In a particular embodiment, the firstlaser 102 and the second laser 120 have different frequencies tofacilitate differentiation of the beams 104, 122 by the detector 114 andto facilitate alignment of the beams 104, 122 by the optics 118.

In a particular embodiment, when the center of the curvilinear pattern106 coincides with the targeting location 110, the controller 124 sendsa fire signal to the first laser 102. In response to the fire signal,the first laser 102 may shine the primary beam 122 on the target 108. Inan illustrative embodiment, the primary beam 122 is aligned with thescanning beam 104 such that the primary beam 122 is directedsubstantially in line with the center of the curvilinear pattern 106. Toillustrate, when the center of the curvilinear pattern 106 coincideswith the targeting location 110, the pointing location of the firstlaser 102 also coincides with the targeting location 110. By scanningthe target 108 using the second laser 120 and by aligning the firstlaser 102 with the center of the curvilinear pattern 106, energy of thefirst laser 102 may be substantially focused on the targeting location110 of the target 108, thereby increasing the amount of the energy ofthe primary energy beam 122 that strikes the targeting location 110.

FIG. 2 depicts a second particular embodiment of a directed energysystem, designated 200. The directed energy system 200 includes acontrol system 202 adapted to facilitate targeting and operation of oneor more directed energy devices, such as a primary laser 218 and atargeting laser 220. The control system 202 may include a number ofinterfaces to facilitate communication with one or more externalsystems, such as a detector interface 208 adapted to interface with adetector 210, a targeting interface 212 adapted to interface with atarget designation system 214 and a laser interface 216 adapted tointerface with the lasers 218, 220. The control system 202 may alsoinclude a processor 204 and a memory 206 accessible to the processor204. The memory 206 may include one or more modules adapted to performvarious functions of the control system 202. For example, the modulesmay include a scanning module 222 and a targeting module 224. Themodules 222 and 224 may be implemented in software (e.g., instructionsstored in a computer-readable medium, such as the memory 206),implemented in hardware, or any combination thereof.

In a particular embodiment, the control system 202 receives targetinformation from the target designation system 214. The targetdesignation system 214 may be adapted to select the particular targetand to determine the target information with respect to the selectedtarget. The target information may include a distance to the target, anorientation of the target, a type of the target, a position of thetarget in space (e.g., coordinates of the target location), a targetinglocation for the target (e.g., a location on the target at which thedirected energy device should be aimed), other information regarding thetarget, or any combination thereof. The control system 202 may receivethe target information and provide the target information to thescanning module 222. The scanning module 222 may determine a curvilinearscanning pattern in which to move the targeting laser 220 based on thetarget information. For example, the curvilinear scanning pattern may beselected such that the radius of the curvilinear scanning pattern issubstantially equal to a distance from a feature on the target to thetarget location of the target. To illustrate, the radius of thecurvilinear scanning pattern may be selected such that a distance fromthe nose of the target to the target location is equal to the radius ofthe curvilinear pattern.

In a particular embodiment, the targeting laser 220 and the primarylaser 218 are aligned such that a pointing direction of the primarylaser is aligned with the center of the curvilinear pattern. Thetargeting module 224 may be adapted to determine when the center of thecurvilinear scanning pattern coincides with the targeting location. Forexample, the targeting module 224 may receive a detection signal fromthe detector 210 via the detector interface 208. The detection signalmay be analyzed by the targeting module 224 to determine when the centerof the curvilinear scanning pattern coincides with the target location.When the center of the curvilinear scanning pattern coincides with thetarget location, the targeting module 224 may send a fire signal to theprimary laser 218. The primary laser 218 may fire a high energy lasersubstantially at the center of the curvilinear scanning pattern. Thus,the primary laser 218 may be directed at the targeting location of thetarget based on the detected reflections from the targeting laser 220.

FIG. 3 depicts a third particular embodiment of a directed energysystem, designated 300. The directed energy system 300 includes a highenergy laser (HEL) 302 and a targeting laser 306. A HEL beam 304 of theHEL 302 and a scan beam 308 of the targeting laser 306 are aligned andpointed via shared optics, such as a beam expander 310, a HEL alignmentmirror 316, and a co-alignment mirror 324. A scan system tilt sensor 320monitors alignment of the beams 304, 308 and generates control signals322, 330 to adjust the alignment of the beams 304, 308.

The HEL 302 projects the HEL beam 304 to an aperture sharing element(ASE) that splits the HEL beam 304. A main portion of the HEL beam 304is directed out via the beam expander 310 toward a target. A sampleportion of the HEL beam 304 is directed to a retroreflector 314. Theretroreflector 314 reflects the sample portion of the HEL beam 304 viathe ASE 312 to the HEL alignment mirror 316. The HEL alignment mirror316 directs the sample portion of the HEL beam 304 to a scan system tiltsensor 320 via a beam splitter 318.

The targeting laser 306 projects the scan beam 308 to the co-alignmentmirror 324. The co-alignment mirror 324 reflects the scan beam 308toward the beam splitter 318. The beam splitter 318 separates the scanbeam 308 into two portions, a main portion and a sample portion. Thesample portion passes through the beam splitter 318 to shine on the scansystem tilt sensor 320. Based on the sample portion of the HEL beam 304and the sample portion of the scan beam 308, the scan system tilt sensor320 may generate the control signals 322, 330 to adjust alignment of theHEL beam 304 and the scan beam 308. In a particular illustrativeembodiment, the beams 304, 308 may be aligned such that the HEL beam 304is directed substantially to an average center of the scan beam 308. Toillustrate, an HEL alignment control signal 322 may be used to adjustthe HEL alignment mirror 316 to substantially center the HEL beam 304 onthe scan system tilt sensor 320. Subsequently, a scan coalign feedbackcontrol signal 330 may be used to adjust the coalignment mirror 324 toalign the beams 304, 308.

The scan co-alignment control signal 330 is sent from the scan systemtilt sensor 320 to a demodulator 332 that distinguishes between thefrequencies of the HEL beam 304 and the scan beam 308 based on amodulation signal received from a modulator 334. The demodulatorgenerates a scan coalign command 336 used to drive the coalignmentmirror 324. The modulator 334 modulates the scan beam 308 so that thescan beam 308 and the HEL beam 304 are distinguishable. For example, thebeams 304, 308 may have different frequencies based on the modulator334.

The main portion of the scan beam 308 is directed to a scan mirror 326.The scan mirror 326 is movable based on a scan command input 328. Forexample, the scan mirror 326 may rotate to move the scan beam in acurvilinear pattern. The scan mirror 326 reflects the main portion ofthe scan beam 308 through the beam expander 310 via the HEL alignmentmirror 316. The particular curvilinear pattern formed by the scan beam308 may be selected based on information about the target, such as anorientation of the target, a type of the target, a distance to thetarget, a targeting location on the target, other information about thetarget, or any combination thereof. Energy of the scan beam 308reflected by the target may be received and analyzed and used todetermine when the pointing direction of the HEL beam 304 is alignedwith the targeting location of the target. When the HEL beam 304 ispointed at the target location of the target, the HEL 302 may beinitiated to shine the HEL beam 304 on the target. Thus, the HEL beam304 may be projected onto the targeting location without expendingenergy of the HEL beam 304 while the HEL beam 304 is not aligned withthe targeting location.

FIGS. 4-9 depict various embodiments of targeting directed energysystems at targets 402. FIG. 4 depicts a first particular embodiment inwhich a directed energy device, such as a laser, is directed toward atarget 402 and moves in a curvilinear pattern 404. In the embodimentdepicted in FIG. 4, a center 401 of the curvilinear pattern 404 is notaligned vertically with the target 402. Such an arrangement may occurwhen a targeting laser is initially scanned in the curvilinear pattern404 toward the target 402 in an attempt to center the curvilinearpattern 404 at a targeting location 406 of the target 402. Toillustrate, the targeting laser may be pointed generally at the target402 based on target information. The initial scans of the targetinglaser may not be centered at the targeting location 406, and thus, maybe misaligned in the manner illustrated in FIG. 4.

A reflection signal 403 based on reflected energy of the targeting laseris also depicted in FIG. 4. The reflection signal 403 illustrates onecomplete scan cycle of the targeting laser. The reflection signal 403includes a long period with no reflection indicated by 420 whichcorresponds to a portion of the curvilinear pattern 404 above the target402. The reflected signal 403 also includes a reflection peak 422corresponding to a portion of the curvilinear pattern 404 when thetargeting laser is reflected from the target followed by a relativelyshort period of no reflection 424 corresponding to the portion of thecurvilinear pattern 404 below the target 402. The period of noreflection 424 is followed by another reflection peak 426 correspondingto the second reflected signal from the curvilinear pattern 404.

When the target 402 is relatively uniform in dimension, the reflectionpeaks 422 and 426 may be substantially equal. Thus, the relatively longperiod of no reflection 420, the relatively short period of noreflection 424, and the relatively even reflection peaks 422 and 426 mayindicate that the curvilinear pattern 404 is above or below the target402. By comparing the reflection signal 403 with information about thecurvilinear pattern of the targeting laser, the approximate directionand distance of the center 401 of the curvilinear pattern 404 to acenter line 410 of target 402 can be determined. Thus, the reflectionsignal 403 can be used to align the center 401 of the curvilinearpattern 404 with the center line 410 of the target 402.

In a particular embodiment, the center 401 is aligned vertically withanother portion of the target 402. For example, when the target location406 is not on the center line 410 of the target 402, an expectedreflection signal can be determined based on geometric informationregarding the target 402 and the received reflection signal 403 can becompared to the expected reflection signal to adjust the curvilinearpattern 404 to align the center 401 of the curvilinear pattern 404 withthe target location 406 vertically. Additionally, while the illustratedtarget 402 has a generally cylindrical shape with a long axis roughlyhorizontal, as shown in FIG. 4, the reflection signal 403 can be used toalign the center 401 of the curvilinear pattern 404 with a targetoriented in any direction (as discussed further with reference to FIG.8).

FIG. 5 depicts a second particular embodiment of targeting a directedenergy system. In FIG. 5, the center 401 of the curvilinear pattern 404is substantially aligned vertically with the center line 410 of thetarget 402. Thus, the vertical misalignment depicted in FIG. 4 has beencorrected in FIG. 5. However, the center 401 of the curvilinear pattern404 is not aligned with the targeting location 406.

In this situation, the reflection signal 403 may include substantiallyeven periods of no reflection 428 and 432 and substantially evenreflection peaks 430 and 434. The relative dimensions of the reflectionpeaks and periods of no reflection may depend upon dimensions of thecurvilinear pattern 404 and the geometry of the target 402. For example,when the target 402 has uneven dimensions, the reflection peaks 430 and434, the periods of no reflection 428 and 432, or both may not be even.To illustrate, when the target 402 is tapered such that it has a crosssection closer to the nose that is smaller than the cross section closerto the tail, the reflection peaks 430 and 434 may be uneven and theperiods of no reflection 428 and 432 may be substantially even.Information about the geometry and orientation of the target can be usedto determine an expected reflection signal 403 when the curvilinearpattern is aligned vertically with the center line 410 (or otherlocation) of the target 402.

FIG. 6 depicts a third particular embodiment of targeting a directedenergy system in which the center 401 of the curvilinear pattern 404 issubstantially aligned vertically with the center line 410 of the target402 and substantially aligned horizontally with the targeting location406 of the target 402. As depicted in FIG. 6, the curvilinear pattern404 has been selected such that a radius of the curvilinear pattern 404is the same as the distance from a nose 408 of the target 402 to thetargeting location 406. That is, the distance from the targetinglocation 406 to the nose 408 corresponds to the distance from the center401 to the curvilinear pattern 404. The radius of the curvilinearpattern 404 may be selected based on the type of the target, theorientation of the target, the distance to the target, other informationregarding the target, or any combination thereof.

The reflection signal 403 in FIG. 6 includes a first reflection peak 436corresponding to the intersection of the curvilinear pattern with thenose 408 of the target 402. The reflection signal 403 also includes aperiod of no reflection 438 corresponding to a portion of thecurvilinear pattern 404 above the target 402. The reflection 403 alsoincludes a reflection peak 440 corresponding to a portion of thecurvilinear pattern 404 reflected from the body of the target 402. Thereflection peak 440 is followed by a period of no reflection 442corresponding to a portion of the curvilinear pattern 404 below thetarget 402. In a particular embodiment, the first reflection peak 436 isrelatively small compared to the second reflection peak 440 as a resultof the cross section of the nose 408 being tapered for air dynamicspurposes. Thus, the relatively small first reflection peak 436 mayindicate that the curvilinear pattern 404 has reached the nose 408 ofthe target 402. Since the radius of the curvilinear pattern 404 wasselected to correspond to the distance from the nose 408 to thetargeting location, when the reflection signal 403 indicates that thecurvilinear pattern 404 has intersected the nose 408 of the target 402,the center 401 of the curvilinear pattern 404 is approximately at thetargeting location 406 horizontally. Additionally, when the periods ofnon reflection 438 and 442 are approximately even, the center 401 of thecurvilinear pattern 404 is approximately aligned vertically with thecenter line 410 of the target 408. Thus, based on the reflection signal403 of FIG. 6, the center 401 of the curvilinear pattern 404approximately corresponds to the targeting location 406 on the target408. In a particular embodiment, a primary or high energy laser isaligned with the center 401 of the curvilinear pattern 404 and may befired at the target 408 after the reflection signal 403 illustrated inFIG. 6 is detected. Accordingly, the primary or high energy laser beammay shine on the targeting location 406 without using energy of theprimary or high energy laser to determine proper alignment of the beamwith the targeting location 406.

FIG. 7 depicts a fourth particular embodiment of targeting a directedenergy system in which the curvilinear pattern 404 extends beyond thenose 408 of the target 402. The reflection signal 403 of FIG. 7 includesa period of no reflection 444 and a single reflection peak 446. Theperiod of no reflection 444 corresponds to a portion of the curvilinearpattern 404 that does not overlap the target 402, and the reflectionpeak 446 corresponds to the portion of the curvilinear pattern 404 thatoverlaps the target 402. The curvilinear pattern 404 overlaps the target402 only once rather than twice during a complete scan cycle. Thepresence of a single reflection peak 446 thus indicates that thecurvilinear pattern 404 is projected beyond the target 402. Since theradius of the curvilinear pattern may be selected to correspond to thedistance from the nose 408 to the targeting location 406, the reflectionsignal 403 of FIG. 7 may indicate that the center 401 of the curvilinearpattern 404 is further forward on the target 402 than the targetinglocation 406.

FIG. 8 depicts a fifth particular embodiment of targeting a directedenergy system in which an orientation of the target 402 is nothorizontal. That is, the center line 410 of the target 402 is at anangle 414 relative to horizontal 412. In a particular embodiment, theorientation of the target 402 is provided to the directed energy system(e.g., a primary laser, targeting lasers, or controller as discussedwith references to FIGS. 1-3). In another particular embodiment, thedirected energy system determines the orientation of the target byanalyzing the reflection signal 403 with respect to information aboutthe curvilinear pattern 404.

As illustrated in FIG. 8, when the orientation of the target 402 is atan angle with respect to horizontal 412 (and the curvilinear pattern 404overlaps the target in two places), the reflection signal 403 mayinclude a first period of no reflection 448 and a second period of noreflection 452. For example, as illustrated, the first period of noreflection 448 corresponds to a portion of the curvilinear pattern 404above the target, and the second period of no reflection 452 correspondsto a second portion of the curvilinear pattern below the target. Thereflection signal 403 may also include reflection peeks 450 and 454.When the curvilinear pattern 404 is reflected twice from the target 402,as illustrated in FIG. 8, and when the target 402 is substantiallyuniform in cross section, the reflection peeks 450 and 454 may be even.In an illustrative embodiment, the first period of no reflection 448 andthe second period of no reflection 452 may be uneven. The position ofthe reflection peaks 450 and 454 and periods of no reflection 448 and452 in the scan cycle of the reflection signal 403 are related to theangle 414 of the target 402 with respect to horizontal 412. In aparticular embodiment, the timing of the first period of no reflection448 and the second period of no reflection 452 may be analyzed (alongwith information about the curvilinear pattern 404 and information aboutthe geometry or type of the target) to determine the angle 414.

FIG. 9 depicts a sixth particular embodiment of targeting a directedenergy system in which the curvilinear pattern 404 is modulated ordithered to determine whether the reflection signal 403 corresponds tothe targeting location 406 being aligned with the center 401 of thecurvilinear pattern 404. Several curvilinear patterns 404, 405 and 404′are illustrated. The first curvilinear pattern 404 (indicated by thedashed line) corresponds to the first reflection signal 403. The firstcurvilinear pattern 404 is undithered and unmodulated. For example, thefirst curvilinear pattern may be substantially the same as thecurvilinear pattern 404 illustrated and discussed with reference to FIG.6 where the curvilinear pattern 404 crosses the nose 408 of the target402.

The second curvilinear pattern 405 is a modulated pattern. Modulatingthe pattern refers to elongating the pattern while keeping the center401 of the curvilinear pattern 404 roughly stationary. For example, theunmodulated pattern 404 may be substantially circular and the modulatedpattern 405 may be substantially elliptical. In a particular embodiment,where the target 402 has a long axis (e.g., along the center line) and ashort axis (e.g., across the body), the modulated curvilinear pattern405 is elongated along the long axis of the target. For example, themodulated pattern 405 may be elongated roughly along the center line ofthe target 402.

The third curvilinear pattern 404′ corresponds to a dithered pattern.Dithering refers to shifting the center of the curvilinear pattern 404from a first location (at 401) to a second location (at 401′). Thus,dithering changes the location of the center of the curvilinear pattern404, while modulating changes the shape of the curvilinear pattern. In aparticular embodiment, the curvilinear pattern is both dithered andmodulated.

The reflection signal 403′ corresponds to one complete dithered ormodulated scan cycle. In a particular embodiment, when the curvilinearpattern 404 generates the first reflection signal 403 (havingsubstantially equal periods of no reflection 456, 460, a relativelyshort reflection peak 462 and a relatively long reflection peak 458 asdiscussed with reference to FIG. 6) the center 401 of the curvilinearpattern 404 may be aligned with the targeting location 406. However,some targets may have local features (e.g., a sensors, antennas,radomes, pitot tubes, winglet, fin etc.) that may cause a similarpattern to the reflection signal 403 to be returned. To determine thatthe reflection signal 403 corresponds to alignment of the center 401 ofthe curvilinear pattern 404 with the targeting location 406, thecurvilinear pattern 404 may be modulated or dithered. In particularembodiments, the curvilinear pattern may be modulated or dithered at afrequency less than the scan cycle. That is, the curvilinear pattern mayvary continuously according to a modulation or dithering period thatoccurs over more than one scan cycle. Additionally, the curvilinearpattern may be dithered or modulated only after a reflection signal 403is received indicating that the nose 408 of the target 402 may have beenreached or the curvilinear pattern may be dithered or modulatedcontinuously or occasionally.

The modulated or dithered curvilinear pattern 404′, 405 may generate areflected signal similar to the reflection signal 403′. That is, thereflection signal may include a relatively large period of no reflection464 corresponding to the portion of the modulated or ditheredcurvilinear pattern 404′, 405 that does not overlap by the target 402and a single reflection peak 466 corresponding to a portion of themodulated or dithered curvilinear pattern 404′, 405 that overlaps thetarget 402. Since the modulated or dithered curvilinear pattern 404′,405 extends beyond the nose 408 of the target 402, no reflection peakmay be received from the nose 408. If a local feature were causing therelative short reflection peak 462 of the unmodulated and unditheredcurvilinear pattern 404, a reflection signal 403 more similar to thereflection signal 403 illustrated and discussed with reference to FIG. 5may be expected. However, where the reflection signal 403 received fromthe unmodulated and undithered curvilinear pattern 404 is due to thecurvilinear pattern 404 having reached the nose 408 of the target 402,the reflection signal 403′ may be expected from the modulated ordithered curvilinear pattern 404′, 405. The modulation or dithering ofthe curvilinear pattern may be accomplished over several scanningcycles, thus the reflection signal 403 and the reflection signal 403′may be separated by one or more complete scanning cycles or partialscanning cycles.

FIG. 10 depicts a flow chart of a first particular embodiment of amethod of targeting a directed energy device. The method includes, at1002, shining a first directed energy device, such as a first laser,onto a target. The first laser may be shined onto the target based ontargeting information provided by targeting sensors. For example, thefirst laser may be shined on the target based on radar reflectionsignals, sonar reflection signals, optical detection signals or otherelectromagnetic or sound based targeting systems. The first laser may bea relative low power targeting laser which shares optics with a secondlaser. The second laser may include a relatively high power laser orhigh energy laser (HEL).

The method also includes, at 1004, determining a type of the target. Thetype 1005 of the target may include information about the geometry ofthe target, speed of the target, a targeting location on the target,other information about the target, or any combination thereof. In aparticular embodiment, the type 1005 of the target may be determinedbased on the targeting information as described above. The method mayalso include, at 1008, determining an orientation 1007 of the target.The orientation 1007 of the target may be determined based on thetargeting information, or may be determined based on reflected energy ofthe first laser.

In a particular embodiment, the method includes, at 1010, selecting atargeting location of the target. The targeting location of the targetmay be determined based on the type of the target 1005, the orientationof the target 1007, or other information related to the target or itsposition. The targeting location is a location on the target at whichenergy of the primary laser (or other directed energy device) should bepointed to damage, disable or destroy the target.

The method also includes, at 1011, determining a curvilinear patternbased at least partially on the targeting location. For example, thecurvilinear pattern may be determined such that a radius of thecurvilinear pattern corresponds to a distance from a feature of thetarget to the targeting location, at 1012. That is, when the curvilinearpattern crosses the feature, the center of the curvilinear pattern maycorrespond to the targeting location of the target. In anotherparticular embodiment, determining the curvilinear pattern based atleast partially on the targeting location includes modulating thecurvilinear pattern. For example, at 1014, the radius of the curvilinearpattern may be varied periodically to distinguish local features of thetarget from the end points of the target. In another particularembodiment, determining the curvilinear pattern based at least partiallyon the targeting location includes dithering the curvilinear pattern.For example, the center of the curvilinear pattern may be shiftedperiodically to distinguish local features of the target from end pointto the target.

The method also includes, at 1016, moving the first laser in thecurvilinear pattern over the target. For example, the first laser may bescanned in the curvilinear pattern over the target and, at 1018,reflections of the first laser from the target may be detected. At 1020,a second directed energy device (e.g., a second laser) may be pointed atthe target based on the detected reflections. For example, the secondlaser may be aligned with the first laser such that the second laserpoints substantially at the center of the curvilinear pattern.

In a particular embodiment, the detected reflections are analyzed todetermine when the center of the curvilinear pattern substantiallycoincides with the targeting location, at 1022. When the center of thecurvilinear pattern substantially coincides with the targeting location,the second laser may be shined on the target, at 1024.

FIG. 11 depicts reflection signals from a targeting system. Thereflection signals simulate detected reflections of a targeting laserused to scan a target in a curvilinear pattern. The reflection signalsinclude first reflections 1102 (shown in solid line) based on anunmodulated pattern and second reflections 1104 (shown in dashed line)based on a modulated pattern.

The simulated reflection signals 1102, 1104 include a plurality of largereflection peaks 1101 corresponding to reflections from a body of thetarget and a plurality of periods of no reflection 1103 corresponding toperiods of time when the curvilinear pattern is not reflected by thetarget. The reflection signals also include a plurality of smallreflection peaks 1105 corresponding to periods of time when thecurvilinear pattern is reflected by a nose of the target or anotherportion of the target with a relatively small reflection cross-section.

The unmodulated reflection signals 1102 appear to indicate that thecurvilinear pattern has reached the nose of the target. Accordingly, thecenter of the curvilinear pattern should correspond to the targetinglocation of the target. The modulated reflection signals 1104 showreflections from the target based on modulating the curvilinear patternto determine whether the nose of the target has been reached or a localfeature of the target has been reached. By analyzing the modulatedreflection signals 1104 with respect to information about thecurvilinear pattern, the targeting system may determine that the nose ofthe target has been reached and may shine a second laser on the targetto strike the target location.

Although the systems and methods disclosed have been described primarilywith respect to laser devices, the systems and methods may also be usedto target other devices, such as a particle beams, masers, acousticbeams, or other directed energy devices. The targeting systems describedmay sense the full aperture of an outgoing beam and may not use anyenergy of the primary device (e.g., a high energy laser) for targeting.Rather a secondary device (e.g., a targeting laser) focuses throughoptics shared with the primary device. The primary device and thetargeting device may have different frequencies to facilitate alignmentof beams from each device and to facilitate detection of reflectionsfrom a target from each device.

While atmospheric disturbances can degrade targeting and/oreffectiveness of some directed energy systems, embodiments disclosedherein may mitigate the effect of atmospheric disturbances as a resultof the targeting laser and primary laser sharing optics. For example,the primary laser and targeting laser can be aligned at the laseroptics, and therefore may be affected similarly by atmosphericconditions. Thus, when the targeting laser is centered about thetargeting location based on reflections of the targeting laser, theprimary laser is also aligned with the targeting location.

Additionally, the targeting system does not require power of the primarybeam for sampling target location, thus conserving the power of theprimary beam. Further, the targeting system uses the entire outputaperture of the primary system and shares the optics of the primarylaser. Thus, the targeting laser and the primary laser may be subject tosimilar errors that may arise in the optics such that alignment of theprimary laser and the secondary laser limits error of the pointingdirection and the pointing location of the primary laser.

In a particular embodiment, one or more of the functions of the directedenergy systems discussed with reference to FIGS. 1-3, above may beimplemented using software executed by a general purpose computingsystem. For example, the controller, scanning system, control system,target designation system, scan system tilt sensor, modulator, ordemodulator of FIGS. 1-3, may include or be included within a computingsystem. In other particular embodiments, one or more functions of thedirected energy systems may be implemented using dedicated hardware,such as application specific integrated circuits, programmable logicarrays and other hardware devices, constructed to implement one or moreof the methods described herein. Accordingly, the present systemencompasses software, firmware, and hardware implementations.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the structure of the variousembodiments. The illustrations are not intended to serve as a completedescription of all of the elements and features of apparatus and systemsthat utilize the structures or methods described herein. Many otherembodiments may be apparent to those of skill in the art upon reviewingthe disclosure. Other embodiments may be utilized and derived from thedisclosure, such that structural and logical substitutions and changesmay be made without departing from the scope of the disclosure. Forexample, method steps may be performed in a different order than isshown in the illustrations, or one or more method steps may be omitted.Additionally, the illustrations are merely representational and may notbe drawn to scale. Certain proportions within the illustrations may beexaggerated, while other proportions may be reduced. Accordingly, thedisclosure and the figures are to be regarded as illustrative ratherthan restrictive.

Moreover, although specific embodiments have been illustrated anddescribed herein, it should be appreciated that any subsequentarrangement designed to achieve the same or similar results may besubstituted for the specific embodiments shown. This disclosure isintended to cover any and all subsequent adaptations or variations ofvarious embodiments. Combinations of the above embodiments, and otherembodiments not specifically described herein, will be apparent to thoseof skill in the art upon reviewing the description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b) and is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Inaddition, in the foregoing Detailed Description, various features may begrouped together or described in a single embodiment for the purpose ofstreamlining the disclosure. This disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, the claimed subject matter may be directed toless than all of the features of any of the disclosed embodiments. Thus,the following claims are incorporated into the Detailed Description,with each claim standing on its own as defining separately claimedsubject matter.

1. A method, comprising: selecting a curvilinear pattern based at leastpartially on a distance from a feature of a target to a targetinglocation on the target; shining a first laser onto the target; movingthe first laser in the curvilinear pattern over the target; detectingreflections of the first laser from the target; and pointing a secondlaser at the target based on the detected reflections.
 2. The method ofclaim 1, wherein the curvilinear pattern is substantially circular. 3.The method of claim 1, wherein the curvilinear pattern has a longer axiscorresponding to a long axis of the target and a shorter axiscorresponding to a shorter axis of the target.
 4. The method of claim 1,wherein the second laser is pointed substantially at a center of thecurvilinear pattern.
 5. The method of claim 1, further comprisingshining the second laser on the target through optics shared with thefirst laser.
 6. The method of claim 1, further comprising: selecting thetargeting location on the target; determining a distance from thefeature of the target to the targeting location; and determining thecurvilinear pattern based at least partially on the distance.
 7. Themethod of claim 6, wherein the targeting location is selected based atleast partially on a type of the target and an orientation of thetarget.
 8. The method of claim 1, wherein the curvilinear pattern isselected to have a radius substantially equal to the distance from thefeature of the target to the targeting location.